Project Summary This application is for the renewal of the Study to Help the AIDS Research Effort (SHARE), which has been the Baltimore-Washington DC site of the Multicenter AIDS Cohort Study (MACS) since 1984. The MACS was established with sites in Baltimore-Washington, Chicago, Pittsburgh, and Los Angeles, initially to study the natural history of HIV infection in men who have sex with men and later, with the advent of effective combination antiretroviral therapy (cART), the treated history of HIV infection, including the relationship between long-term controlled HIV infection and chronic diseases and co-morbidities associated with aging. To reflect these changing priorities in HIV research, SHARE has had subsequent enrollments to balance proportions of HIV- and HIV+ men and to reflect the HIV epidemic more accurately. Men enrolled have been followed semi annually since 1984 or enrollment and have a) provided questionnaire data, physical exam data, laboratory data (including HIV serostatus, T cell subset measurements, and HIV viral load measurements), and a large repository of plasma, serum, cryopreserved peripheral blood mononuclear cells, and other specimens; and these have permitted SHARE and MACS to make major contributions to the understanding of treated and untreated HIV disease, and comorbidities associated with increased survival due to antiretroviral treatment. The present application, in response to RFA-HL-19-008, aims to extend followup of the SHARE cohort (about 640 men) from 2019 to 2026, to allow merger of SHARE (and the other MACS sites) with the nine sites of the Women?s Interagency HIV Study (WIHS) into a single cohort, termed the MACS-WIHS Combined Cohort Study (CCS), that will include both men and women. The specific aims of the CCS are outlined in a parallel application from the putative Data and Coordinating Center (DACC) of the CCS, and the 10 Specific Aims of that single cohort are outlined in the DACC application for the CCS; these include Cardiovascular (CV), Pulmonary/Sleep (PS), Neurocognitive NC), Aging (AG), Cancer, HIV Pathogenesis (PA), Psychosocial (PS), Health Disparities, Platform (PL), and Career Development (CD) Aims. The specific aims of the SHARE Clinical Research Site (CRS) are to: 1) play a leading role in the achievement 7 of these Aims by the CCS (i.e., CV, PS, AG, PA, PS, PL, and CD), including serving as a reading center for echocardiography and sleep studies; 2) to contribute to the achievement of the other 3 CCS aims, and 3) to implement all applicable CCS protocols and support the scientific goals of the CCS. Local initiatives on inflammation and physical activity will also support these aims, which take full advantage of the extensive follow-up and repository of biological specimens already available from this cohort and which will be extended under this proposal, enabling further contributions to our understanding and care of comorbidities and other health issues faced by people living with HIV today.